An international team of astronomers has discovered the smallest known lava super-Earth with an atmosphere that redirects heat from the planet's dayside to its nightside, according to infohub.kz.
The findings on the unusual rocky super-Earth HD 3167 b, located 154 light-years from Earth, were published in The Astrophysical Journal Letters. Due to its extreme proximity to its host star, a year on this exoplanet lasts just one Earth day. The planet is tidally locked: one side always faces the star, while the other is perpetually in darkness.
Observations were made using the MIRI infrared instrument aboard the James Webb Space Telescope during a secondary eclipse. Astronomers had expected to record a scorching dayside, but the actual temperature of HD 3167 b turned out to be significantly lower than the theoretical maximum.
The study's authors, including University of Chicago associate professor Edwin Kite and graduate student Brandon Park Coy, concluded that the planet's retained atmosphere reflects starlight and redistributes heat to the nightside. As a result, it has become the coldest known lava planet with an atmosphere.
The research was conducted as part of a program led by University of Maryland astronomer Megan Weiner Mansfield, who studies 10 different lava worlds. Scientists emphasize that studying such exoplanets helps better understand the early stages of Earth's formation, when its surface was covered by an ocean of magma during the first million years of the Solar System's existence.